Method for supplying gas while dividing to chamber from gas supply facility equipped with flow controller

摘要

A method for supplying a specified quantity Q of processing gas while dividing at a desired flow rate ratio Q1/Q2 accurately and quickly from a gas supply facility equipped with a flow controller into a chamber. When a specified quantity Q of gas is supplied while being divided at a desired flow rate ratio Q1/Q2 from a gas supply facility equipped with a flow controller into a reduced pressure chamber C through a plurality of branch supply lines and shower plates fixed to the ends thereof, pressure type division quantity controllers FV1 and FV2 are provided in the plurality of branch supply lines GL1 and GL2. Opening control of both division quantity controllers FV1 and FV2 is started by an initial flow rate set signal from a division quantity control board FRC for fully opening the control valve CV of the pressure type division quantity controller having a higher flow rate and pressures P3' and P3'' on the downstream side of the control valve CV are regulated thus supplying a total quantity Q=Q1+Q2 of gas while dividing into the chamber C through orifice holes (3a, 4a) made in shower plates (3, 4) at desired division quantities Q1 and Q2 represented by formulas Q1=C1P3' and Q2=C2P3'' (where, C1 and C2 are constants dependent on the cross-sectional area of the orifice hole or the gas temperature on the upstream side thereof).